我有一些代码加载到一些空的部分和项目中。然后，如果存在网络连接，则会对可见单元进行一些调用。我在每个部分都有一个按钮，它根据使用 indexPath 的部分类型导航到另一个视图。我的问题是，当我删除第一个部分时，cellProvider 不会更新 indexPath 并且按钮导航到错误的视图。但是，如果我滚动，问题就会消失。如何确保 indexPath 更新？编辑：看来我的 headerViews 保留了旧的 indexPath，但 cellProvider 正确更新。滚动并返回后，标题视图将设置为正确的 indexPath。
private enum RowItemType: Hashable {
case itemTypeOne(collection: MyCollection)
case itemTypeTwo(collection: MyCollection)
case itemTypeThree(collection: OtherCollection)
}
private enum SectionType: Hashable {
case sectionOne
case sectionTwo
case sectionThree
}
class MyCollection: Codable, Hashable, Equatable {
var identifier = UUID()
var foos: [Foo]
init(foos: [Foo] = [Foo]()) {
self.foos = foos
}
// MARK: Equatable
var hash: Int {
var hasher = Hasher()
hasher.combine(identifier)
return hasher.finalize()
}
static func == (lhs: MyCollection, rhs: MyCollection) -> Bool {
lhs.identifier == rhs.identifier
}
func hash(into hasher: inout Hasher) {
hasher.combine(identifier)
}
}
class OtherCollection: Codable, Hashable, Equatable {
var identifier = UUID()
var bars: [Bar]
init(bars: [Bar] = [Bar]()) {
self.bars = bars
}
// MARK: Equatable
var hash: Int {
var hasher = Hasher()
hasher.combine(identifier)
return hasher.finalize()
}
static func == (lhs: OtherCollection, rhs: OtherCollection) -> Bool {
lhs.identifier == rhs.identifier
}
func hash(into hasher: inout Hasher) {
hasher.combine(identifier)
}
}
final class SomeTableViewController: UITableVIewController {
...code....
RELEVENT CODE
private func makeDataSource() -> UITableViewDiffableDataSource<SectionType, RowItemType> {
UITableViewDiffableDataSource(tableView: tableView, cellProvider: { [weak self] tableView, indexPath, item in
guard let self = self else {
return UITableViewCell()
}
guard let marginTableView = tableView as? AutoMarginTableView else {
return UITableViewCell()
}
switch item {
case .itemTypeOne(collection: let collection):
let carousel = self.itemOneCarouCell(from: marginTableView, withSection: .sectionOne, atIndexPath: indexPath)
if !collection.foos.isEmpty {
carousel.configureCell(with: .sectionOne, fooCollection: collection)
self.showViewAllButtonForHeader(collection.foos.count > 3, atIndexPath: indexPath)
} else {
carousel.configureCellForLoading()
self.getFoosTypeOne(collection: collection)
}
return carousel
case .itemTypeTwo(let collection):
let carousel = self.itemTwoCarouCell(from: marginTableView, withSection: .sectionTwo, atIndexPath: indexPath)
if !collection.foos.isEmpty {
carousel.configureCell(with: .sectionTwo, fooCollection: collection)
self.showViewAllButtonForHeader(collection.foos.count > 3, atIndexPath: indexPath)
} else {
carousel.configureCellForLoading()
self.getFoosTypeTwo(collection: collection)
}
return carousel
case .ttemTypeThree(let collection):
let carousel = self.itemThreeCarouCell(from: marginTableView, withSection: .sectionThree, atIndexPath: indexPath)
if !collection.bars.isEmpty {
carousel.configureCell(with: collection)
self.showViewAllButtonForHeader(true, atIndexPath: indexPath)
} else {
carousel.configureCellForLoading()
self.getBars(collection: collection)
}
return carousel
})
}
private func showViewAllButtonForHeader(_ show: Bool, atIndexPath indexPath: IndexPath) {
if let headerView = self.tableView.headerView(forSection: indexPath.section) as? MyTableHeaderView {
UIView.animate(withDuration: 0.5, delay: 0.0, options: .curveEaseInOut, animations: {
headerView.showViewAll(show)
}, completion: nil)
}
}
private func getFoosTypeOne(collection: MyCollection) {
var snapshot = dataSource.snapshot()
if FeatureFlags.isFeatureEnabled && snapshot.sectionIdentifiers.contains(.sectionOne) {
someRepositry.getfoos { result in
if case .success(let foos) = result {
if !foos.isEmpty {
collection.foos = foos
snapshot.reloadItems([.itemTypeOne(collection: collection)])
} else {
if snapshot.sectionIdentifiers.contains(.sectionOne) {
snapshot.deleteSections([.sectionOne])
}
}
self.dataSource.apply(snapshot, animatingDifferences: true)
}
}
}
}
private func getFoosTypeTwo(collection: MyCollection) {
var snapshot = dataSource.snapshot()
if FeatureFlags.isFeatureEnabled && snapshot.sectionIdentifiers.contains(.sectionTwo) {
someRepositry.getDifferentFoos { result in
if case .success(let foos) = result {
if !foos.isEmpty {
collection.foos = foos
snapshot.reloadItems([.itemTypeTwo(collection: collection)])
} else {
if snapshot.sectionIdentifiers.contains(.sectionTwo) {
snapshot.deleteSections([.sectionTwo])
}
}
self.dataSource.apply(snapshot, animatingDifferences: true)
}
}
}
}
private func getBars(collection: OtherCollection) {
var snapshot = dataSource.snapshot()
someService.getSomeCollection { someColl in
DispatchQueue.main.async {
if let someColl = someColl {
if !someColl.bars.isEmpty {
collection.bars = someColl.bars
snapshot.reloadItems([.itemTypeThree(collection: collection)])
} else {
if snapshot.sectionIdentifiers.contains(.sectionThree) {
snapshot.deleteSections([.sectionThree])
}
}
}
self.dataSource.apply(snapshot, animatingDifferences: true)
}
}
}
}
extension SomeTabelViewController: SomeTableHeaderViewDelegate {
func someTableHeaderViewTappedViewAll(_ headerView: SomeTableHeaderView) {
guard headerView.section < dataSource.numberOfSections(in: tableView) else {
return
}
let snapshot = dataSource.snapshot()
let section = snapshot.sectionIdentifiers[headerView.section]
switch section {
case .sectionOne:
if case .itemTypeOne(let collection) = snapshot.itemIdentifiers(inSection: .sectionOne).first, !collection.foos.isEmpty {
let vc = SomeListViewController()
navigationController?.pushViewController(vc, animated: true)
}
case .sectionTwo:
if case .itemTypeTwo(let collection) = snapshot.itemIdentifiers(inSection: .sectionTwo).first, !collection.foos.isEmpty {
let vc = SomeListViewController()
navigationController?.pushViewController(vc, animated: true)
}
case .sectionThree:
if case .itemTypeThree(let collection) = snapshot.itemIdentifiers(inSection: .sectionThree).first, !collection.bars.isEmpty {
let vc = OtherViewController(collecton: collection)
navigationController?.pushViewController(vc, animated: true)
}
}
}